Please show steps. I think B should be 22.8 cm. A narrow single slit (in air) is
ID: 1701538 • Letter: P
Question
Please show steps. I think B should be 22.8 cm.
A narrow single slit (in air) is illuminated by IR from a He-Ne laser at 1152.2 nm. and it is found that the center of the tenth dark spot lies at an angle of 6.2degree off the central axis. Determine the width of the slit. A. 1.07 times 10 -4m If a screen is 2.0 m away, where on the screen is located the tenth bright spot above the central maximum? A 0.22 m At what angle would the tenth minimum appear if the entire arrangement were immersed in water (n = 1.33) instead of air (1.00029) A. 4.92degreeExplanation / Answer
The wave length of the light is = 1152.2 nm
The number of the dark fringe is m = 10
The angle = 6.2o
1) The condition for the nth dark is
a sin = n/2
Slit width 2a = n/sin = 10*1152.2 nm/ sin6.2 = 1.07*10^-4 m
2) The screen distance is D = 2m
Then the condition for the nth dark is
a*y/D = n
The location of the tenth bright spot is y = nD/a = 10*1152.2 nm*2/1.07*10^-4 m = 0.22 m
3) The condition for the nth dark when immersed in water is
a sin = n/2
Slit width sin = n/2a = 10*1152.2 nm/1.33*1.07*10^-4 m
= 4.65o